DURKOPP ADLER 291 Operating instructions

Contents page:

Preface and general safety instructions

Part 1: Operating Manual, Class 768

1. Product description

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2. Designated use

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3. Subclasses

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4. Ancillary equipment

. . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5. Technical data

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

6. Operation

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

6.1 Threading the needle thread . . . . . . . . . . . . . . . . . . . . . . . . 9

6.2 Adjusting the needle-thread tension . . . . . . . . . . . . . . . . . . . 9

6.3 Opening the needle-thread tensioners . . . . . . . . . . . . . . . . . . 9

6.4 Adjusting the thread regulator . . . . . . . . . . . . . . . . . . . . . . . 10

6.5 Winding on the looper thread . . . . . . . . . . . . . . . . . . . . . . . 11

6.6 Fitting the looper-thread bobbin . . . . . . . . . . . . . . . . . . . . . . 12

6.7 Adjusting the looper-thread tension . . . . . . . . . . . . . . . . . . . . 13

6.8 Fitting and changing the needle . . . . . . . . . . . . . . . . . . . . . . 14

6.9 Raising the sewing feet . . . . . . . . . . . . . . . . . . . . . . . . . . 15

6.10 Locking the sewing feet in the up position . . . . . . . . . . . . . . . . 15

6.11 Adjusting the sewing-foot stroke . . . . . . . . . . . . . . . . . . . . . 16

6.11.1 Adjusting the sewing-foot stroke mechanically . . . . . . . . . . . . . . 16

6.11.2 Rapid electro-pneumatic stroke adjustment (HP) . . . . . . . . . . . . 17

6.12 Adjusting the sewing-foot pressure . . . . . . . . . . . . . . . . . . . . 18

6.13 Adjusting the stitch length . . . . . . . . . . . . . . . . . . . . . . . . . 18

7. Keypad on sewing-machine arm

. . . . . . . . . . . . . . . . . . . . 19

7.1 Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

7.2 LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

GB

Ausg./Edition: 07/99

Contents page:

8. Control and operating panel

. . . . . . . . . . . . . . . . . . . . . . 20

8.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

8.2 Operating-panel keys . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

8.3 Operating the V810 control unit . . . . . . . . . . . . . . . . . . . . . 22

8.4 Changing parameter values . . . . . . . . . . . . . . . . . . . . . . . 23

8.5 Direct parameter-number selection . . . . . . . . . . . . . . . . . . . 23

9. Sewing

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

10. Maintenance

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

10.1 Cleaning and inspection . . . . . . . . . . . . . . . . . . . . . . . . . 26

10.2 Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

11. Ancillary equipment

. . . . . . . . . . . . . . . . . . . . . . . . . . . 30

11.1 Seam-centre guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

1. Product description

The

DÜRKOPP ADLER 768

is a special sewing machine with universal applications.

•

Two-needle double-lockstitch pillar sewing machine with underfeed, needle feed

and alternating-foot overfeed

•

Robust design based on the proven modular system of the class 767.

•

Low-maintenance design (maintenance-free antifriction and sintering bearings,

articulated thread lever with permanently-lubricated roller bearings)

•

Automatic non-pressurised recirculating lubrication with sight glasses for oil level

and circulation. Shuttle lubrication must be carried out manually.

•

Maximum space beneath raised sewing feet: 16 mm.

•

Stroke of alternating sewing feet adjustable by adjusting wheel on arm up to a

maximum of 7 mm.

•

Large vertical shuttle with bobbin-housing lift.

•

A safety coupling on the lower toothed-belt wheel protects the shuttle from being

displaced or damaged if the thread jams in the shuttle track.

•

Fitted as standard with pedal-operated electro-pneumatic sewing-foot lift.

•

Fitted as standard with electro-pneumatic rapid stroke-adjustment with automatic

stitch rate limit, operated by knee switch or ergonomically-placed key on the

sewing-machine arm.

Automatic, infinitely-variable adjustment of stitch rates as a function of the stroke

height set.

2. Designated use

The

768

is a special sewing machine designed for sewing heavy material. Such

material is generally made of textile fibres, but it may also be leather. It is used in the

clothing industry and for domestic and motor-vehicle upholstery.

This sewing machine can also be used to produce so-called technical seams. In this

case, however, the operator must assess the possible dangers which may arise (with

which

DÜRKOPP ADLER AG

would be happy to assist), since such applications are on

the one hand relatively unusual and, on the other, they are so varied that no single set

of criteria can cover them all. The outcome of this assessment may require appropriate

safety measures to be taken.

Generally only dry material may be sewn with this machine. The material may be no

thicker than 10 mm when compressed by the lowered sewing feet. The material may not

contain any hard objects, since if it does the machine may not be operated without an

eye-protection device. No such device is currently available.

The seam is generally produced with textile-fibre sewing thread of gauge 10/3 NeB

(cotton), 10/3 Nm (synthetic) or 10/4 Nm (covering yarn). Before using any other thread

the possible dangers arising must be assessed and appropriate safety measures taken

if necessary.

This special sewing machine may be set up and operated only in dry, well-maintained

premises. If the sewing machine is used in other premises which are not dry and

well-maintained it may be necessary to take further precautions (which should be

agreed in advance - see EN 60204-3-1: 1990).

As manufacturers of industrial sewing machines we proceed on the assumption that

personnel who work on our products will have received training at least sufficient to

acquaint them with all normal operations and with any hazards which these may involve.

GB

5

3. Subclasses

Class 768-274-FLP-HP:

Two-needle double-lockstitch pillar sewing machine with

underfeed, needle feed and alternating-foot overfeed

4. Ancillary equipment

order no. ancillary equipment

9822 510125 light-guide sewing lamp

with mains cable and rocker switch, for fitting to the

sewing-machine arm

9880 767001 sewing-lamp fitting set

for light-guide sewing lamp 9822 510125

9822 510001 WALDMANN sewing lamp (halogen)

with 12V/20W bulb for fitting to the sewing-machine arm

0907 487519 sewing-lamp fitting set

for sewing lamp 9822 510001

0798 500088 230V sewing-light transformer

with mains cable, no switch,

for sewing lamps 9822 510001 and 9822510125

9781 000002 WE-6 filter controller

0797 003031 pneumatic connection set

For the pneumatic connection of frames with maintenance units and

pneumatic ancillary equipment. Consists of connection hose

(length 5 m, diameter 9 mm), hose nozzles, hose ties and

plug-and-socket connector.

No.depending tape guide

with tape-roll holder

on tape width

N800 005611 seam-centre guide

5. Technical data

Noise:

workplace emission value (DIN 45635-48-A-1-KL2)

Lc = 85 dB (A)

stitch length: 9,6 mm

sewing-foot stroke: 1,5 mm

stitch rate: 1.400 min

-1

material: 4-play Skai, 1,6 mm 900 g/m

2

Lc = 86 dB (A)

stitch length: 9,6

sewing-foot stroke: 5,6 mm

stitch rate: 1.400 min

-1

material: 4-play Skai, 1,6 mm 900 g/m

2

6

needle system: 134-35

needle thickness (depending on E No.):

- min. [Nm] 140

- max. [Nm] 200

- standard [Nm] 180

needle gap (depending on E No.):

- min. [mm] 8

- max. [mm] 14

max. sewing-thread thicknesses:

- cotton [NeB] 10/3

- synthetic thread [Nm] 10/3

- covering yarn [Nm] 10/3

bobbin capacity:

- synthetic thread Nm 20/3: [m] approx. 22

- synthetic thread Nm 30/3: [m] approx. 35

max. stitch rate: [rpm] 2400

max. stitch length:

- forwards: [mm] 12

- backwards: [mm] 12

max. material thickness: [mm] 10

stroke height alternating sewing feet:

- max. [mm] 7

- ex works [mm] 1 - 6

feed stroke (above needle plate): [mm] 1.2

max. passage beneath sewing feet:

- lift [mm] 16

operating pressure: [bar] 6

air consumption per working cycle (FLP and HP): [NL] approx. 0.2

sewing drive: [type] Efka DC1600/DA82GA

rated power: [kW] 0.75

rated voltage: 1 x 230 V, 50 / 60 Hz

frames: [type] MG55-3

dimensions (H x W x D): [mm] 1570 x 1060 x 600

working height (ex works): [mm] 950

weight:

- sewing-machine upper part [kg] approx. 56

- frames with sewing drive [kg] approx. 46

GB

7

Fig. a:

correct thread loop in the centre of

the material

Fig. b:

needle-thread tension too low

or looper-thread tension too great

Fig. c:

needle-thread tension too great

or looper-thread tension too low

1

2

3

8

6. Operation

6.1 Threading the needle thread

Caution - danger of injury !

Turn off the main switch!

The needle thread may only be threaded with the sewing

machine switched off.

–

Thread the needle thread as shown in the illustration.

6.2 Adjusting the needle-thread tension

Pre-tensioners 1

The pre-tensioners 1 should be set at a lower tension than the main tensioners 3.

–

Adjust the pre-tensioners 1 by turning the knurled nuts.

–

After making major changes to the pre-tensioners 1, readjust the main tensioners 3.

Main tensioners 3

The main tensioners 3 should be set to the minimum possible tension.

The looping of the threads must be in the centre of the material (see fig. a).

With thin material excessive thread tension can cause unwanted gathering and thread

breakage.

–

Adjust the main tensioner 2 so that the stitches are uniform.

Supplementary tensioner 2

The supplementary tensioner 2 can be switched in to effect a rapid change in

needle-thread tension during operation (e.g. with thickened seams, on the flap when

backstitching the front edge of a jacket or overcoat).

–

Set the supplementary tensioner 2 lower than the main tensioner.

–

The supplementary tensioner 2 is switched on during operation at the keypad on

the sewing-machine arm.

When the supplementary tensioner is switched on the LED over the relevant key

lights up.

6.3 Opening the needle-thread tensioners

The main tensioners 3 and supplementary tensioner 2, if it is switched on, open

automatically:

–

when the sewing feet are lifted electro-pneumatically (see section 6.9).

GB

9

6.4 Adjusting the thread regulator

The thread regulator 1 regulates the amount of needle thread necessary for stitch

formation.

The setting depends on the following factors: - material thickness

- yarn characteristics

- stitch length

A properly-adjusted thread regulator ensures an ideal sewing result at a minimum

needle-thread tension.

At the correct setting the needle-thread loop must slide at low tension over the thickest

point of the shuttle.

Caution - danger of injury!

Turn off the main switch.

The thread regulator may only be adjusted with the sewing

machine switched off.

–

Undo both screws 2.

–

Move the thread regulator 1.

The thread regulator is fitted with slots for this purpose.

Moving in the

"+"

direction increases the quantity of needle thread

Moving in the

"-"

direction reduces the quantity of needle thread

–

Tighten screws 2.

+

-

1

2

10

6.5 Winding on the looper thread

Caution - danger of injury !

Turn off the main switch.

The looper thread may be threaded for spooling only with

the sewing machine switched off.

The looper thread may be spooled only with the sewing

feet locked in the raised position.

–

If spooling is to take place when sewing with no underlaid material:

lock the sewing feet in the raised position (see section 6.9).

–

Thread the looper thread as shown in the illustration.

–

Wind about 5 loops of the looper thread anti-clockwise onto the bobbin core.

–

Place the bobbin on bobbin-winder shaft 2.

–

Swivel bobbin-winder lever 3 against the bobbin.

–

Adjust tension 1.

The looper thread should be wound on with minimal tension.

–

Sew.

The bobbin-winder lever 3 terminates the process as soon as the bobbin is full.

B

C

E

1 2

3

GB

11

6.6 Fitting the looper-thread bobbin

Caution - danger of injury!

Turn off the main switch.

The looper-thread bobbin may only be changed with the se-

wing machine switched off.

Removing the empty looper-thread bobbin

–

Raise the sewing foot.

–

Open shuttle cover 3.

–

Raise bobbin-housing flap 1.

–

Remove upper part of bobbin-housing 2.

–

Remove empty looper-thread bobbin.

Threading looper thread

–

Place full bobbin 4 in the upper part of bobbin-housing 2:

When the thread is unwound the bobbin must rotate

in the opposite direction

(see arrow).

–

Draw looper thread through slit 5 beneath tensioning spring 6.

–

Thread looper thread through hole 7 in the upper part of bobbin-housing 2.

–

Trim looper thread to approx. 3 cm.

–

Insert upper part of bobbin-housing 2 with full bobbin into the shuttle.

–

Close bobbin-housing flap 1.

–

Close shuttle cover 3.

1 2 3

4

2 5 6 7

12

6.7 Adjusting the looper-thread tension

Caution - danger of injury!

Turn off the main switch.

The looper-thread tension may only be adjusted with the se-

wing machine switched off.

Adjusting the tensioning spring 2

–

Open the shuttle cover.

–

Adjust the tensioning spring 2 with regulating screw 3.

to increase looper-thread tension = turn screw 3 clockwise

to decrease looper-thread tension = turn screw 3 anti-clockwise

–

Close shuttle cover.

2 3

1

3 2

GB

13

6.8 Fitting and changing the needle

Caution - danger of injury!

Turn off the main switch.

Needles may only be changed with the sewing machine

switched off.

–

Turn the handwheel until the needle rod 1 has reached its highest point.

–

Undo screw 3.

–

Withdraw needle downwards from needle holder 2.

–

Insert new needle as far as it will go into the hole in needle holder 2.

Caution:

When seen from the operating side of the machine the furrow 4 of the right-hand

needle must point to the right and the furrow of the left-hand needle to the left

(see sketch).

–

Tighten screw 3.

CAUTION:

When a thicker needle is fitted the distance from the

shuttle to the needle must be corrected

(see servicing instructions).

Failure to comply with this instruction can cause the following faults:

when fitting a thinner needle: -faulty stitches

-damage to thread

when fitting a thicker needle: -damage to the shuttle tip

-damage to the needle

1

2

3

4

14

6.9 Raising the sewing feet

The

class 768

pillar sewing machine is fitted with the electro-pneumatic sewing-foot lift

(FLP) as standard. This enables the sewing feet to be raised during sewing.

–

Push pedal half-way back.

–

The sewing machine halts in the 1st position (needles down).

Raising the sewing feet.

–

Release pedal.

–

Push pedal forwards.

The sewing machine begins sewing at the rate set by the pedal.

6.10 Locking the sewing feet in the up position

The electro-pneumatically raised sewing feet are locked in the up position with the

lever 1 (e.g. to spool the looper thread or change the sewing feet).

The lever 1 is located at the rear of the sewing-machine arm.

–

With the machine at a halt push the pedal half-way back.

Raising the sewing feet.

–

Swivel lever 1 down.

The sewing feet are locked in the up position.

–

Swivel lever 1 up.

The sewing feet are no longer locked.

1

GB

15

6.11 Adjusting the sewing-foot stroke

6.11.1 Adjusting the sewing-foot stroke mechanically

The height of the sewing-foot stroke is adjusted with adjusting wheel 1 on the arm cover.

Caution - danger of injury

The sewing-foot stroke may only be adjusted with

the sewing machine switched off.

–

Turn adjusting wheel 1. min.,

A, B, C, D, E, F, max.

min. = minimum sewing-foot stroke

max. = maximum sewing-foot stroke

Automatic stitch rate limit

The sewing-foot stroke and stitch rate are mutually dependent (see table).

A potentiometer is mechanically connected to adjusting wheel 1. The control system

registers the set sewing-foot stroke via this potentiometer and limits the stitch rate.

stitch-length range adjusting cam sewing-foot max. stitch rate

[mm] [position] stroke [mm] [rpm]

min.

2400

A

1.5 2350

B

2.4 2200

0 - 8

C

3.3 2050

D

4.2 1950

E

5.1 1750

F

6.0 1650

max.

1600

8 - 12 min. - max. 1600

B

C

E

1

16

6.11.2 Rapid electro-pneumatic stroke adjustment (HP)

The

class 768

pillar sewing machine is fitted with rapid electro-pneumatic stroke

adjustment (HP) as standard.

Maximum sewing-foot stroke can be activated while sewing for additional thicknesses in

the material or to oversew cross-seams as follows:

–

Press keypad key 1 on the sewing-machine arm.

OR:

–

Operate knee-switch 2 beneath the table plate.

Rapid stroke adjustment: operating mode

How long maximum sewing-foot stroke remains active depends on which operating

mode has been set. Three operating modes are available.

They are set with parameters F-138 and F-184 on the operating panel

(see motor-manufacturer’s guide (supplied)).

Operating

mode

Operation / Explanation

Press and

hold

F-138 = off

F-184 = 0

Maximum sewing-foot stroke remains active for as long as key 1

or knee-switch 2 is pressed.

Press and

release

F-138 = on

Maximum sewing-foot stroke is activated by pressing key 1 or

knee-switch 2.

Pressing the key or knee-switch again deactivates maximum

sewing-foot stroke again.

Press and

hold with

minimum

stitch rate

F-138 = off

F-184 > 0

Maximum sewing-foot stroke remains active for as long as key 1

or knee-switch 2 is pressed.

After the key or knee-switch is released the machine continues

sewing until the pre-set minimum stitch rate (parameter F-184) is

reached with maximum sewing-foot stroke. The seam is then

continued at normal sewing-foot stroke.

1

2

GB

17

6.12 Adjusting the sewing-foot pressure

The sewing-foot pressure is adjusted with knob 1.

–

to increase sewing-foot pressure = turn knob 1 clockwise

to decrease sewing-foot pressure = turn knob 1 anti-clockwise

6.13 Adjusting the stitch length

The stitch length is adjusted with knob 2.

–

to increase stitch length = turn knob 2 clockwise

to decrease stitch length = turn knob 2 anti-clockwise

–

To sew bar-tacks manually press stitch-regulating lever 3 down.

The machine sews backwards for as long as the stitch-regulating lever 3 is held

down.

The stitch length is the same as that set for sewing forwards.

DURKOPP ADLER 291 Operating instructions

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DURKOPP ADLER 291 Operating instructions

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